JBL S4800, Руководство пользователя

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The new S4800 employs a 3-way,
three-driver design, incorporating
an ultrahigh-frequency (UHF) com-
pression driver and horn to repro-
duce high frequencies up to 40kHz.
With the UHF handling the ultrahigh
frequencies, the high-frequency
(HF) transducer could then be
upgraded to a new design using a
3-inch diaphragm for better repro-
duction of lower frequencies and
better blend with the woofer than
the older generations’ 2-inch
diaphragm. Both compression drivers are mounted in a unique
combination Bi-Radial
® horn struc-
ture, precision-molded from JBL’s
proprietary SonoGlass
™ material, an
extremely dense and mechanically
inert substance that is easily
molded into the unusual shapes
required for superior acoustic
performance.
In order to re-create the extremely
high dynamic range provided by
today’s audio sources, a new low-
frequency transducer was used,
incorporating a ferrite magnet, 3-
inch edge-wound voice coil, and
an Aquaplas-coated 15-inch cone
made of Kevlar
® composite, a mix-
ture of Kevlar fiber and pulp mate-
rial that provides increased rigidity.
An EPDM rubber surround was
chosen for both its flexibility and
long life. The Symmetrical Field
Geometry
™ (SFG ™ ) magnetic struc-
ture minimizes second harmonic
distortion by providing a uniform
flux field that prevents uneven
cone movement. The rigid cast-
aluminum frame is also designed
to minimize distortion, as alu-
minum has no effect on the mag-
netic field. Extensive computer-
aided engineering and design effort
made to develop the optimized port
tuning employed in the S4800 has
resulted in a significant advance in
the concept of state-of-the-art bass
reproduction. This proprietary align-
ment method offers the best damp-
ing characteristics and provides
extremely fast alignment, eliminat-
ing the typical “bass-reflex” sound
of a ported system.
All three transducers are built using
the most advanced materials and
precision manufacturing techniques
refined from renowned JBL profes-
sional sound systems.
High power-handling capability
results in no limitations on the types
of source material. The S4800 has
very high input sensitivity; even a
relatively small high-end amplifier
can provide full dynamic range
without compression.
Despite its power and sophistica-
tion, the S4800 embodies both tradi-
tion and technology. It reflects the
design, engineering and manufac-
turing expertise derived and refined
through nearly six decades of
experience that are the exclusive
province of one loudspeaker
builder – JBL.
4
SonoGlass
Bi-Radial Horn
100˚ Horizontal
60˚ Vertical
Curved
Dress
Panel
Spiked Feet
Foot Base
1" MDF
Construction
1500FE
15" LF
Driver
Port
Tube
435AL
3" HF
Compression
Driver
045Ti 1" UHF
Compression
Driver
Figure 1. Cutaway view of S4800 speaker system.
CHAPTER 1 – THE S4800 LOUDSPEAKER:
A TRIUMPH IN ACOUSTICS AND TECHNOLOGY
S4800 OM 10/11/05 1:51 PM Page 4